[Spirit.]

Hey!
I just wanted to add something else to what everyone has said. No, there's not even a slim chance that she's pregnant. First, is that, yes, when sperm hits air, it dies. Second, out of more than millions of sperm that compete to fertilize an egg, only one even gets to fertilize the egg, and for that one to fertilize an egg is highly improbable since most of them would have been dead. Either that, or they wouldn't have been able to make it to the egg to fertilize it because it requires moving up the V and being exposed causes them to die, and if not, become weaker, if you will. And all she can't get pregnant, simply because you didn't have intercourse. Yes, you do need to be in her to get her pregnant.
So I'd say there's probably a 99.5% chance she's NOT pregnant. So you needn't worry. And yes, getting her period next month will be a sure sign that she isn't pregnant.

Take care, and don't worry too much.